1. Field of the Invention
The present invention relates to an electronic automatic accompaniment apparatus for harmonizing automatic accompaniment with performance of a player on a basis of a preliminarily memorized accompaniment pattern and/or an accompaniment pattern selected by the player.
2. Description of the Prior Art
In a conventional automatic accompaniment apparatus of this kind, various kinds of accompaniment patterns are memorized in accordance with each style of musical tune such as rock music, country music or the like. In operation of the accompaniment apparatus, an accompaniment pattern is selected from the memorized accompaniment patterns by operation of a player to automatically harmonize the selected accompaniment with an input chord applied from a keyboard. In general, the accompaniment patterns each are composed of a set of tone pitch data indicative of each tone pitch of accompaniment tones and timing data indicative of a sound timing. The tone pitch data is represented by key-codes on a basis of predetermined chords such as C Major or the like and is produced as a source pattern taking into account of tone pitch conversion effected in accordance with the type and root of the input chord. In operation of the accompaniment apparatus, the key-codes of the source pattern are converted in tone pitch in accordance with the type of the input chord applied from the keyboard, and all the converted tone pitches are shifted in accordance with the root of the input chord to produce an accompaniment tone at a tone pitch harmonized with the input chord.
In addition, the shift data of the key-codes is memorized as a note conversion table in accordance with the type of the input chord to convert the source pattern in tone pitch in compliance with the type of the input chord. Thus, the shift data is read out from the note conversion table in compliance with the type of the input chord and calculated as the key-code of the source pattern to obtain a suitable accompaniment pattern in accordance with the type of the chord.
The accompaniment pattern includes, however, ornamental tones other than the chord constituent notes. It is, therefore, required to convert the ornamental tones in tone pitch in accordance with the kind of the accompaniment pattern in order to obtain an optimal accompaniment pattern. As a result, a producer of the pattern is forced to produce the note conversion table for each source pattern or each kind of accompaniment patterns for effecting the tone pitch conversion.